1. Field of the Invention
The present invention relates to a peptide capable of synthesizing silica from a silica precursor in an aqueous solution whose conditions include normal temperature, a normal pressure and a near-neutral weak base, and use thereof.
2. Discussion of Related Art
Development of new useful resources has been raised as an important national issue for the future due to the exhaustion of ground resources materials caused by a sudden increase in consumption of limited available resources after the industrialization. Therefore, advanced countries such as US, EU and Japan has focused their national capacities to develop and ensure new source materials. In addition, as global warming and climate change caused by the environmental pollution serve as factors which threaten the survival of the human race, a new paradigm has appeared to seek for the economic growth and protection of environment at the same time.
A method of producing a new material through environmentally friendly biological production using marine resources is expected to be a technique for playing important roles in ensuring original technology and achieving national low-carbon green growth with growth of environmentally friendly industries. Since silica is able to covalently bind to certain chemical species, it plays an important role in synthesis of a new hybrid material (i.e., an organic-inorganic complex), and also has an excellent characteristic of making up for the weak points of respective materials as biocompatible materials. In recent years, an industrial production process of silica has problems in that it requires the conditions of high temperature, and strong acid or base, and environmentally harmful by-products may be produced.
However, as enzymes and peptides for biosynthesizing silica from extracts of marine living organisms such as a sponge and a diatom or based on their genetic information have been found, development of a marine-derived bio-silica composite material has been issued all over the world due to the applicability of an environmentally friendly bio-silica produced by the enzymes and peptides, and various uses thereof (Cha et al., 2000, Nature 403:pp. 289-292; Kroger et al, 1999, Science 286: pp. 1129-1132; Poulsen & Kroger, 2004, J Biol Chem 279: pp. 42993-42999; Shimizu et al, 1998, Proc Natl Acad Sci USA 95: pp. 6234-6238). Since the bio-silica material can be prepared into a proper formulation for various applications, and is expected to exhibit excellent energy efficiency, mechanical/chemical properties, biologically synthetic activities and mass productivity, it is very important to possess the original technology for ensuring a biological catalyst for bio-silica material production.
Silaffin produced by the diatom has 260 amino acid residues, which are degraded into peptides having 7 repeated sequences during a maturation stage. In this case, each of the peptides serves as a template and a catalyst for silica synthesis. Silicatein that is an enzyme for synthesizing silica produced by the sponge has a highly conserved amino acid sequence among the sponge species, but peptides for synthesizing silica produced by the diatom have poorly conserved amino acid sequences but show structural similarities after post-translational modification.